package com.pzh.assignment.common.shiro.bean;

import cn.hutool.json.JSONUtil;
import com.auth0.jwt.interfaces.DecodedJWT;
import com.baomidou.mybatisplus.core.toolkit.StringUtils;
import com.pzh.assignment.common.bean.Result;
import com.pzh.assignment.common.utils.JwtUtils;
import lombok.extern.log4j.Log4j2;
import org.apache.shiro.authc.AuthenticationException;
import org.apache.shiro.authc.AuthenticationToken;
import org.apache.shiro.authc.ExpiredCredentialsException;
import org.apache.shiro.web.filter.authc.AuthenticatingFilter;
import org.apache.shiro.web.util.WebUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import org.springframework.web.bind.annotation.RequestMethod;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

@Log4j2
@Component
public class JwtFilter extends AuthenticatingFilter {


    @Autowired
    JwtUtils jwtUtils;

    @Override
    protected AuthenticationToken createToken(ServletRequest servletRequest, ServletResponse servletResponse) throws Exception {

        HttpServletRequest request = (HttpServletRequest) servletRequest;
        String jwt = request.getHeader("Authorization");
        if (StringUtils.isEmpty(jwt)){
            return null;
        }

        return new JwtToken(jwt);
    }

    @Override
    protected boolean onAccessDenied(ServletRequest servletRequest, ServletResponse servletResponse) throws Exception {
        HttpServletRequest request = (HttpServletRequest) servletRequest;
        String jwt = request.getHeader("Authorization");
        if (StringUtils.isEmpty(jwt)){
            return true;
        }else{

            //校验jwt
            DecodedJWT tokenInfo = jwtUtils.getTokenInfo(jwt);
            if(jwtUtils.isTokenExpired(tokenInfo.getExpiresAt())){
                throw new ExpiredCredentialsException("token已失效，请重新登录");
            }
            //执行登录
            return executeLogin(servletRequest,servletResponse);
        }

    }

    @Override
    protected boolean onLoginFailure(AuthenticationToken token, AuthenticationException e, ServletRequest request, ServletResponse response) {
        HttpServletResponse httpServletResponse = (HttpServletResponse) response;

        Throwable throwable = e.getCause() == null ? e : e.getCause();
        Result result = Result.fail(throwable.getMessage());
        String json = JSONUtil.toJsonStr(result);

        try {
            httpServletResponse.getWriter().print(json);
        } catch (IOException ex) {
            ex.printStackTrace();
        }


        return false;
    }

    /**
     * 解决跨域问题
     *      在请求到达Controller之前必须先经过filter，这里也得做跨域放行处理
     * @param request
     * @param response
     * @return
     * @throws Exception
     */
    @Override
    protected boolean preHandle(ServletRequest request, ServletResponse response) throws Exception {

        HttpServletRequest httpServletRequest = WebUtils.toHttp(request);
        HttpServletResponse httpServletResponse = WebUtils.toHttp(response);
        httpServletResponse.setHeader("Access-Control-Allow-Origin",httpServletRequest.getHeader("Origin"));
        httpServletResponse.setHeader("Access-Control-Allow-Methods"," GET,POST,OPTIONS,PUT,DELETE");
        httpServletResponse.setHeader("Access-Control-Allow-Headers",httpServletRequest.getHeader("Access-Control-Request-Headers"));
        //跨域是会首先发送一个OPTIONS请求，这里我们给OPTIONS请求直接返回正常状态
        if (httpServletRequest.getMethod().equals(RequestMethod.OPTIONS.name())){
            httpServletResponse.setStatus(org.springframework.http.HttpStatus.OK.value());
            return false;
        }

        return super.preHandle(request, response);
    }
}
